Potential genotoxic effects of GSM-1800 exposure on human cutaneous and nerve cells
Résumé
Introduction The GSM-1800 signal has been in use for several years in Europe and questions raised about its potential biological effects , in view of the fact that, with respect to GSM-900, the increase in the carrier frequency corresponds to a more superficial absorption in the tissues. Consequently, the skin becomes an even more important target for the absorption of the radiofrequency radiation (RFR) emitted by mobile phones. Nevertheless, brain tissues remain a critical target. Cells In order to determine whether RFR at 1800 MHz could behave as a genotoxic agent, skin and brain cells were exposed to a 217-Hz-modulated GSM-1800 signal and assayed using the comet assay: (i) normal human epidermal keratinocytes (NHEK) and dermal fibroblasts (NHDF) which are cutaneous cells from epidermis and dermis respectively, and (ii) the SH -SY5Y and CHME-5 human cell lines, which are neuroblastoma and microglial cells, respectively. Exposure The RFR exposure system that was used in these experiments was manufactured by IT'IS (Zurich, Switzerland). It consists in two shorted waveguides allowing to run exposed and sham conditions at the same time in the same culture incubator, at 37°C, 5% CO 2. It is controlled by a software, which provides blind conditions until completion of data analysis. The specific absorption rate (SAR) used was 2 W/kg, corresponding to the public exposure limit recommended by ICNIRP and the exposure duration was 48 hours. Comet assay At the end of the exposure, cells were removed from their Petri dish by trypsin/EDTA treatment, counted and 5x10 4 cells were used to detect DNA damage including single DNA breaks. Positive controls were performed using hydrogen peroxydase (1%, 1 hour). The genotoxic effects were detected using the alkaline comet assay kit (TrevigenÒ slides) following the supplier procedure. Under these conditions, 6 independent experiments were performed for each cell type (2 Petri dishes by run). The analysis was done on at least 100 images from two comet slides (one per Petri dish) for each cellular model and exposure condition. Results The analysis of the slides is ongoing. Once the data analysis is completed, IT'IS will break the blinding codes, and the results will be presented at the meeting